Add convenience targets to Makefile #353

Job	Run time
amd64 / build-stellar-core	22m 7s
amd64 / build-stellar-friendbot	46s
amd64 / build-stellar-horizon	4m 1s
amd64 / build-stellar-soroban-rpc	2m 29s
arm64 / build-stellar-core	4h 46m 28s
arm64 / build-stellar-friendbot	2m 53s
arm64 / build-stellar-horizon	10m 13s
arm64 / build-stellar-soroban-rpc	47s
amd64 / build	3m 33s
amd64 / test (testnet)	2m 33s
amd64 / test (pubnet)	2m 33s
amd64 / test (standalone)	1m 55s
amd64 / test (standalone, --enable-horizon-captive-core)	1m 47s
amd64 / push-pr	1m 0s
amd64 / push-release	0s
arm64 / build	7m 53s
arm64 / test (testnet)	12m 57s
arm64 / test (pubnet)	1m 29s
arm64 / test (standalone)	2m 20s
arm64 / test (standalone, --enable-horizon-captive-core)	2m 20s
arm64 / push-pr	1m 18s
arm64 / push-release	0s
manifest / push	11s
complete	1s
	6h 11m 34s

Provide feedback